1. Field of the Invention
The present invention relates to a method and apparatus for processing an image, an image display system, a storage medium, and a program, and more particularly to a method and apparatus for processing an image, an image display system, a storage medium, and a program, capable of smoothly displaying a motion image.
2. Description of the Related Art
There is a need for achieving improved image quality by improving a signal processing technique and/or a technique of driving a display device.
In general, an improvement in image quality is achieved by increasing the resolution of an image thereby achieving a finer image. The amount of information of an image is represented by the number of dots called pixels constituting the image. The number of pixels is represented in the form of the number of horizontal pixels by the number of vertical pixels. Specific examples are 800×600 and 1024×768. The greater the number of pixels (dots), the finer the image and the more the amount of information of the image.
To display an image with higher resolution, it is known to use two displays #1 and #2 such that a left-hand half part of the image is displayed on the display #1 and a right-hand half part of the image is displayed on the display #2 (in a multi mode) thereby achieving resolution twice the resolution achieved by using a single display #1 or #2 (in a single mode). A specific example of this technique may be found, for example, in Japanese Unexamined Patent Application Publication No. 10-124024.
If the resolution of an image is increased, the amount of information of the image increases. As a result, it becomes necessary to transmit a greater amount of data to the display #1 or #2, and thus it becomes necessary to increase the data transmission rate. In the system disclosed in the Japanese Unexamined Patent Application Publication No. 10-124024, to avoid the above problem, the data of each dot of the displays #1 and #2 is converted into a compressed form thereby reducing the amount of data of each dot, and the data in the compressed form is converted into an original form by means of signal processing, thereby making it possible to transmit image data without having to increase the data transmission rate.
For a motion image, the image quality can also be improved by increasing the frame rate, i.e., the number of times the image displayed on a screen is refreshed each second.
For example, when a motion image is displayed by projecting the image on a screen by using a projector, the projector scans each frame line by line in a horizontal direction. When scanning of one frame is completed, scanning of a next frame is started, and thus the motion image is displayed.
As described above, the image quality, in particular, the image quality of a motion image, can be improved by increasing the frame rate. However, to display an image at an increased frame rate, it is necessary to improve a driving circuit so as to be capable of driving a display device at an increased speed and it is also necessary to improve light modulation elements, which determine the intensity of the image, so as to respond at a higher speed. These requirements are difficult to achieve, and the achievement of the requirements results in an increase in cost.
In the case in which, using two displays, an image with resolution twice the resolution that can be achieved by using a single display is displayed, the technique of reducing the amount of data used for each dot of the display thereby making it unnecessary to increase the data transmission rate is already in practical use. However, this technique does not increase the frame rate at which a motion image is displayed. That is, even in a system capable of displaying a high-resolution image using two displays, to smoothly display a motion image, it is still required to increase the operating speed of the driving circuit for driving the displays and increase the response speed of light modulation elements.